Palynological fossils from the Yingzuilazi Formation in Hongmiaozi Basin, northeastern margin of North China Block

This paper reports the palynological fossils found from the Yingzuilazi Formation in Hongmiaozi Basin on the northeastern margin of North China Block, and recognizes a palynological assemblage named Cicatricosisporites-Abietineaepollenites-Piceites. This assemblage is characterized by the dominance of disaccites gymnosperm pollen and Lygodiaceae spore and the moderate abundance of pollen without sacci, with no angiosperm pollen found. The characteristics of this palynological assemblage can be correlated with those of Shahezi Formation in Songliao Basin. The geological age of Yingzuilazi Formation is considered to be Early Cretaceous, as shown by the existence of some typical Early Cretaceous palynological fossils, such as Cicatricosisporites sp., Cicatricosi-sporites undulates and Cicatricosisporites implexus. On the basis of the composition of this assemblage, the authors hold that, during the deposition period of Yingzuilazi Formation, the vegetation was mainly Pinaceae and Taxodiaceae coniferous forests, with a few understory Filicales, the climate was of subtropical zone, and the environment probably had humid or semi-humid features on the northeastern margin of North China Block.